A recent theory holds that humour evolved because it encourages us to perform the arduous task of fact-checking our assumptions about other people’s intentions and perspectives. By this account, mirth is the reward we get when we debunk one of our presumptions and see things suddenly in a new light – jokes are ‘super-normal stimuli’ that exploit this system.

Once it evolved, humour became a social signal – we assume funny people are intelligent and friendly, and men and women alike prefer witty partners. On average, however, men tend to be more concerned that would-be partners will find their jokes funny, whereas women are more attracted to people who make them laugh.

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